Question

how many elements are there in the arithmetic progression​

Answer 1

Step-by-step explanation:

Any arithmetic progression is a, a+d, a+2d, +3d…

and Nth term can be expressed in terms of the first term and the common difference =a+(n-1)*d

Here 10000 is the last term, and 1 is the first term

so 10000 = 1+(n-1)d

=>9999=(n-1)*d, so 9999 is a product of two terms of which one has to be greater than 1

9999 = 101*11*3^2

(n-1) can be either 101 or 3 or 9 or 11, so 4

(source : quora, google)

Answer 2

Answer:

what do u mean by elements??

In general , arithmetic progression means series in the form of a,a+d,a+2d,....a+nd.

where a is 1st term, and l= a+nd is the last term with common difference d.,

then any term will be given by,

tn = a + (n-1)d,

sn = n/2*(a+l) = n/2 [2a +(n-1)d].

Hope it helps u..